Install Atlassian Plugin SDK
Execute atlas-run to run Confluence locally. That will install all the
dependencies using maven. Default login credentials are admin/admin
If it seems that confluence is running wrong version, try clean the environment and force the version by using --version parameter, e.g:
atlas-clean
atlas-run --version 5.2-m19
Configurate Flow plugin like explained in Flowdock's help section.
When running Confluence with atlas-run, Flowdock plugin can be found from
System plugins.